1. Technical Field
The present invention relates to a lead-zirconate-titanate (PZT) amorphous alloy plating solution which may be used to form a PZT amorphous alloy film having excellent mechanical and physical properties and a method for plating a PZT amorphous alloy using the same.
2. Description of the Related Art
In general, lead-zirconate-titanate (PZT)-series oxide ceramics has an empirical composition of Pb1+x(ZryTi1-x)O3, and is widely used in various fields in a film form in addition to a bulk form because it has electrically excellent piezoelectric physical properties, an excellent ferroelectric property, and a pyroelectric property. More specifically, recently, in fabricating sensors and actuators using an MEMS technology complying with needs for a minimum size and integration of electro-mechanical complex parts, there is a growing interest in a PZT-series thin film and thick film having advantages of high sensitivity, high output, and a fast response speed.
The PZT-series oxide ceramics have a piezoelectric characteristic when it is used to form a perovskite structure represented as ABO3. The perovskite structure can be obtained only when stochiometry is accurately matched. In general, lead (Pd) tends to become relatively easily volatile due to a low melting point. Accordingly, when PZT-series oxide ceramics having a perovskite structure are fabricated, excessive Pb of 10-50% is further added to the PZT-series oxide ceramics in order to maintain stochiometry by taking into consideration the low melting point. If such excessive Pb is not fully consumed, but is locally present on Pb or PbO within the PZT-series oxide ceramics, however, it functions as a major cause to lower a breakdown voltage or to deteriorate dielectric/piezoelectric characteristics.
Furthermore, in a perovskite crystal structure in which the PZT-series oxide ceramics represents the piezoelectric characteristics, the stochiometry ratio of x and y in Pbx(ZryTi1-y)O3 needs to have a range of 1≦x≦1.3, 0.1≦y≦0.9. In this case, if a composition of Pb is less than 1, the perovskite crystal structure is not formed, but a flourite or pyrochore crystal structure is formed. Accordingly, the asymmetry of B-sites is lost, and thus the piezoelectric characteristics are not obtained.
However, PZT oxide ceramics having a crystal structure, such as the perovskite, flourite or pyrochore crystal structure, is problematic in that electrical conductivity is low because crystallinity is high.
Korean Patent No. 0504609 (Aug. 3, 2005) proposes a method for fabricating a PZT thin film through chemical vapor deposition (CVD) using a combination of Pb(dpm)2-Zr(OiPr) (dpm)3-Ti(OiPr)2(dpm)2 as a material for gasifying a solution.
However, the prior art is a method for fabricating PZT having a perovskite structure and is problematic in that electrical conductivity because crystallinity is high.